Photochemical or mechanical production of flexible printing plates

ABSTRACT

Flexible printing plates are produced from printing plates consisting essentially of a dimensionally stable substrate (1) and a recording layer (2) by a process in which the printing plate is produced alternatively either by photochemical or by mechanical structuring, and in the case of photochemical structuring the photosensitive recording layer (2) is exposed imagewise and the unexposed parts of the recording layer (2) are washed out with a developer and in the case of mechanical structuring the originally photosensitive, uniformly exposed recording layer (2) is cut imagewise and the nonprinting parts of the recording layer (2) are peeled off from the substrate (1). 
     The printing plates produced by this process are suitable for the production of products printed by the flexographic method and for lacquering products printed by the offset method.

This application is a continuation of U.S. application Ser. No.08/170,986, filed on Dec. 21, 1993, now abandoned, which is a divisionalof U.S. application Ser. No. 08/014,170, filed on Feb. 5, 1993, nowabandoned.

The present invention relates to a process for the production offlexible printing plates from printing plates consisting essentially ofa dimensionally stable substrate and a recording layer, wherein theprinting plates are produced alternatively either by photochemical or bymechanical structuring. The flexible printing plates thus produced aresuitable both for producing products printed by the flexographic methodand for lacquering products printed by the offset method.

Various systems are used as printing plates for offset lacquering.

In solid lacquering, rubber blankets are used. The disadvantage here isthe piling of the still moist offset ink on the rubber blanket. Theprinting process has to be interrupted and the rubber blanket cleaned.

If only a few areas are to be omitted during application of the lacquer,the areas are cut out of the rubber blanket and peeled off manually. Thedisadvantages of this system are insufficient dimensional stability ofthe structured rubber blanket, which prevents lacquer applicationexactly in register during long print runs, distortion of the rubberblanket when the uppermost layer is peeled off, the low resolution andthe piling of the offset ink. Photopolymeric flexographic printingplates are generally used for spot lacquering. The disadvantages hereare the high cost of plate production (film production, exposure,washing out in organic developers, drying and after treatment) and thepiling.

It is an object of the present invention to make the process for theproduction of flexible printing plates for flexographic printing and inparticular for use as offset lacquering plates simpler and morevariable.

We have found that this object is achieved, according to the invention,essentially by a printing plate which, depending on the requiredresolution, can be mechanically structured or imagewise exposed, washedout and dried. Mechanical structuring in this context means that thenonprinting parts are cut out of the printing plate imagewise, forexample by means of a computer-controlled knife or manually, and peeledoff.

The present invention relates to a process for the production of aflexible printing plate from a printing plate consisting essentially ofa dimensionally stable substrate (1) and a recording layer (2), whereinthe printing plate is produced alternatively either by photochemical orby mechanical structuring, in the case of photochemical structuring thephotosensitive recording layer (2) being exposed imagewise and theunexposed parts of the recording layer (2) being washed out with adeveloper and in the case of mechanical structuring the originallyphotosensitive, uniformly exposed recording layer (2) being cutimagewise and the nonprinting parts of the recording layer (2) beingpeeled off the substrate (1).

A protective film (3) may be present on the recording layer (2).

A thin nontacky release layer (2a), which in the case of photochemicalstructuring is removed after the imagewise exposure and in the case ofmechanical structuring is peeled off or washed off before or afterimagewise cutting, may be present between the photosensitive recordinglayer (2) and the protective film (3).

An adhesion-promoting layer (la) may additionally be arranged betweenthe recording layer (2) and the dimensionally stable substrate (1).

A dimensionally stable film of a plastic is preferred as thedimensionally stable substrate (1).

In a preferred embodiment of the novel process, the adhesion of therecording layer (2) to the dimensionally stable substrate (1) or to anadhesion-promoting layer (1a) present on the dimensionally stablesubstrate (1) is more than 1 N/cm and less than 10 N/cm.

In the case of mechanical structuring, the tensile strength of therecording layer (2) is preferably more than 0.2 N/mm² and less than 20N/mm².

In other preferred embodiments of the novel process, the hardness of theexposed recording layer (2) is more than 20 and less than 80 Shore Aand, in the case of photochemical structuring, water or aqueoussolutions are used as developers.

The photosensitive recording layer (2) preferably contains a mixture ofa hydrophobic and a hydrophilic binder in amounts such that the exposedrecording layer (2) washed out with a developer exhibits a weightincrease of >1 and <30% by weight after storage for 24 hours in water atroom temperature.

The present invention furthermore relates to a process for theproduction of products printed by the flexographic method, wherein theprinting plates used are those which are produced by a novel process,and to a process for lacquering products printed by the offset method,wherein lacquer transfer is effected by the printing plates produced bya novel process.

The novel process will now be more particularly described.

The printing plate to be used for the novel process consists essentiallyof a dimensionally stable substrate (1), for example of a dimensionallystable substrate film having a thickness of from 100 to 300 μm, on whicha thin adhesion-promoting layer having a thickness of from 0.1 to 10 μm(1a) has been preferably applied, and the actual recording layer (2)which is applied thereon and may be from about 200 to 8,000 μm thick. Anontacky release layer (2a) which may be from about 1 to 5 μm thick maybe applied to the latter and is advantageous for good adhesion to thenegative during exposure. A protective film or cover sheet (3) having athickness of from about 10 to 200 μm may be present thereon in order toprotect the printing plate from damage.

The recording layer (2) is photosensitive, i.e. it can be crosslinked byimagewise exposure. If the printing plate is to be mechanicallystructured, the recording layer is uniformly crosslinked before cutting,and, where present, the nontacky release layer is removed by washing.

The recording layer (2) can in principle contain all formulations knownfor flexographic printing plates. Usually, such a formulation consistsof one or more elastomeric binders, one or more ethylenicallyunsaturated compounds, a photoinitiator, a stabilizer and, if required,further assistants.

If the conventional block copolymers of styrene and butadiene orisoprene are used as binders, the printing plates exhibit the phenomenonof piling when they are used as offset lacquering plates, i.e. the stillmoist offset printing ink sticks to the printing plate and piles upthere.

This disadvantage is not exhibited by photosensitive mixtures asdescribed in EP-A-0 386 514.

Piling of the offset ink is closely coupled with the swelling of theprinting plate in water-based lacquer. If the swelling of the exposedprinting plate in water-based lacquer is too low (<1% by weight afterstorage for 24 hours), the offset ink becomes attached to the surface ofthe printing plate (=varnishing plate) after only a few sheets have beenprinted. If the swelling is too high (>30% by weight), unacceptable sizechanges and delamination of individual relief elements occur during theprint run.

The formulations stated in EP-A-0 386 514 have the advantage here thatthey contain a hydrophilic and a hydrophobic binder. The swelling of therecording layer in water-based lacquer can therefore be exactly adjustedby means of the amounts of the binder components. Mixtures which containthe hydrophilic and the hydrophobic binder in about equal amounts areoptimal. These formulations exhibit no piling at all and have a longpress life. The swelling in various water-based lacquers is from 3 to15% by weight.

These formulations additionally have the advantage that they can bedeveloped in water or aqueous solutions.

If the printing plates are to be only mechanically structured, therecording layer need not of course be photosensitive and then also neednot be exposed uniformly prior to cutting. It is then possible todispense with the addition of ethylenically unsaturated compounds and aphotoinitiator. However, the combinations of a hydrophilic and ahydrophobic binder, stated in EP-A-386 514, proved to be particularlysuitable also for purely mechanical structuring. These bindercombinations give printing plates having suitable hardness and highresolution in the case of mechanical structuring.

Water-soluble, partially or completely hydrolyzed polyvinyl alcohols andpolyvinyl alcohol/ethylene oxide graft copolymers (cf. for exampleMowiol® 04/86 from Hoechst AG) are suitable as nontacky release layer(2a).

The substrate film (1) preferably has a thickness of from 150 to 300 μm.The substrate film imparts to the printing plate the necessarydimensional stability and should not be deformed when the nonimage partsare peeled off. A 300 μm thick polyethylene terephthalate film proved tobe particularly suitable. To achieve good binding of the substrate filmto the adhesion-promoting layer, it is advantageous to pretreat the filmwith a primer. Pretreated polyethylene terephthalate films arecommercially available (for example from the companies Kalle, Toray andRhone-Poulenc).

As already mentioned above, an adhesion-promoting layer (thickness from0.1 to 5 μm) is preferably present between the substrate film and therecording layer and enables a defined adhesion to be obtained. Theadhesion of the adhesion-promoting layer to the exposed recording layermay be of decisive importance for the quality of imagewise cutting.

If the adhesion to the exposed recording layer is too high, the nonimageparts can be peeled off from the substrate film only with very greatdifficulty, if at all, after cutting. On the other hand, if the adhesionis too low, delamination of individual relief elements occurs during theprinting process. The adhesion should therefore be more than 2 and lessthan 20 N/2 cm. The optimum adhesion is from 5 to 10 N/2 cm.

The adhesion of the exposed recording layer to the substrate film shouldadvantageously also be matched by the tensile strength of the exposedrecording layer.

If it is assumed that a strip about 5 cm wide is to be peeled off whenthe nonimage parts are removed, the material should be able to absorbforces of 12.5 N without tearing in the case of an adhesion of 5 N/2 cm.The tensile strength of a 1 mm thick recording layer should then begreater than 0.25 N/mm².

Furthermore, the tear propagation strength of the exposed material andthe uniformity of tearing are important for the quality of the cuttingresult. The uniformity of tearing can be determined by measuring tearpropagation strength according to DIN 53,507. A scored test specimen isclamped in a tensile tester and the force curve is recorded as afunction of the distance. If the force required to tear the specimen isconstant within +/-2%, the tear is propagated uniformly in the materialat a constant speed, and smooth, satisfactory edges are obtained onimagewise cutting of the exposed printing plate.

If, on the other hand, the force/distance diagram of the exposedrecording layer shows pronounced force peaks, i.e. the force fluctuatesstepwise by more than +/-2%, the tear is propagated nonuniformly in thematerial. The edges of the image elements are then irregularly scored,so that the transfer of information is not sufficiently exact.

The hardness of the exposed recording layer is also of importance.Uniform lacquer application without squash is achieved in particularwith layers whose Shore A hardness is from 30 to 70 units (measuredusing 6 mm thick specimens).

If the printing plate meets all the above-mentioned requirements withregard to the mechanical properties, a resolution of up to 1 mm can beachieved in the case of manual structuring. This means that isolateddots and lines and also negative elements having a size >1 mm can besatisfactorily produced. The resolution of a cut rubber blanket on theother hand is only about 1 cm.

The cutting process can be carried out either manually or in acomputer-controlled cutting apparatus. Manual cutting entails the dangerthat the substrate film will be scored and will lose its stability. Inan automatic cutting apparatus, on the other hand, the lowering of theknife can be very exactly adjusted (+/-20 μm), so that the substratefilm is not damaged. In addition, the cutting speed can be matched tothe material, leading to a further improvement in the cutting result.Automatically operating cutting apparatuses are commercially available(e.g. Marbaplot® from Marbach etc.).

The cut-out elements can be lifted off manually. If the areas to beremoved are too large, it is useful to make additional assisting cutsduring cutting. Strips having a width of up to 5 cm are particularlyeasy to peel off.

The Examples which follow illustrate the invention. Parts andpercentages are by weight unless stated otherwise.

EXAMPLE 1

A photosensitive mixture was processed in a twin-screw extruder (e.g.ZSK 53 from Werner & Pfleiderer). The formulation for the photosensitiverecording layer (2) contains the following components:

40 parts of an ethylene/acrylic acid/acrylate copolymer consisting of60% by weight of ethylene, 20% by weight of acrylic acid and 20% byweight of 2-ethylhexyl acrylate (melt flow index MFI (160° C., 325g)=15)

40 parts of an ethylene/propylene/diene rubber (e.g. Buna AP 251 fromHuls, containing 50% by weight of ethylene and 14 double bonds per 1000carbon atoms and having a Mooney viscosity ML (1+4)/100° C. of 45)

3.0 parts of glycidyl methacrylate

5.0 parts of hexanediol diacrylate

1.0 part of benzil dimethyl ketal

1.0 part of 2,6-di-tert-butyl-p-cresol (Kerobit® TBK)

9.0 parts of butylethanolamine

1.0 part of N-nitroso-N-cyclohexylhydroxylamine (potassium salt)

0.004 part of Safranine T (C.I. 50,240)

The two binders were metered into the twin-screw extruder.

After the melting zone, glycidyl methacrylate, the mixture of hexanedioldiacrylate, benzil dimethyl ketal and 2,6-di-tert-butyl-p-cresol andthen butylethanolamine were metered in. Finally, a 30% strength aqueoussolution of Safranine T and the potassium salt ofN-nitroso-N-cyclohexylhydroxylamine were metered in. The totalthroughput was 20 kg/h. The temperature in the melting zone was about150° C., that in the mixing zone about 130° C. and that in the dischargezone about 115° C.

The solvents were recovered from the melt in a devolatization dome.

The melt discharged from the slot die was passed into the nip (thickness1.3 mm) of a two-roll calender, where the melt was smoothed and wasfirmly bonded to the cover sheet and substrate film running in over thecalender rollers.

The cover sheet used was a 125 μm polyethylene terephthalate film(Mylar® from DuPont de Nemours), which had been coated beforehand on oneside with a 5 μm thick nontacky release layer of a polyvinylalcohol/ethylene oxide graft copolymer (Mowiol® 04/86 from Hoechst AG).

The substrate film used was a 300 μm thick, precoated polyethyleneterephthalate film (e.g. Hostaphan® RN from Hoechst AG). This film wascoated with a mixture of adhesion-forming components in a thickness of 5μm. The mixture of adhesive-forming components used for this purposeconsisted of a mixture of equal amounts of polycarbonate (e.g. Makrolon®2800 from Albis Plastic Chemie GmbH), phenoxy resin (e.g. PKHH fromBrenntag, Mulheim/Ruhr) and an isocyanate-based crosslinking agent (e.g.Desmodur® L from Bayer AG).

The films were introduced into the calender so that the photosensitivemelt was bonded to the nontacky release layer and the adhesion-promotinglayer. Thereafter, the laminate was cooled on a vacuum suction belt andcut to size.

A. Photochemical structuring

The cover sheet was peeled off from the printing plate and a negativewas placed on top. The plate was covered with a vacuum film and wasexposed imagewise to actinic light (wavelength from 350 to 400 μm) for10 minutes in a 70 watt exposure unit under reduced pressure.

The negative was removed and the plate was washed out down to thesubstrate film in 1% strength sodium carbonate solution in a drum-typebrush washer at 50° C. in the course of 12 minutes. The printing platewas then dried for 2 hours at 60° C. and then post-exposed for a further10 minutes.

The printing plate thus obtained is referred to as printing plate (1a).

B.1 Mechanical structuring

The printing plate was exposed uniformly from both sides for 10 minuteswithout applying reduced pressure. The cover sheet was then peeled offand the printing plate was immersed for 10 minutes in 1% strength sodiumcarbonate solution. During this procedure, the thin nontacky releaselayer became detached.

The crosslinked and nontacky printing plate was then placed on thecutting table of a computer-controlled cutting apparatus (Marbaplot fromMarbach), sucked against the table under reduced pressure and cut. Theoriginal produced in the computer contained positive and negativeelements (solid areas, lines, circles and dots) of variable size (from0.5 mm to a few cm). The cutting depth of the knife was adjusted to thethickness of the recording layer plus an additional 20 μm. The cuttingspeed was 3 cm/s.

The printing plate thus obtained is referred to as printing plate (1b).

B.2 Mechanical structuring

The printing plate was exposed uniformly from the front for 10 minuteswithout applying reduced pressure. The cover sheet was then peeled off.The printing plate was then cut using a computer-controlled cuttingapparatus. The nonimage parts were peeled off.

The thin nontacky release layer was then removed by rubbing with a plushpad soaked in a 1% strength sodium carbonate solution.

The printing plate thus obtained is referred to as printing plate (1c).

COMPARATIVE EXAMPLE 1

The mixture below was processed according to Example 1 in a twin-screwextruder. 83 parts of styrene/isoprene/styrene block copolymer(Cariflex® 1107 from Shell)

5 parts of hexanediol diacrylate

5 parts of hexanediol dimethacrylate

5 parts of liquid paraffin (white oil S 5000)

1 part of benzil dimethyl ketal

1 part of 2,6-di-tert-butyl-p-cresol

0.006 part of Sudan Deep Black BB (C.I. 26,150)

The melt was firmly bonded to the cover sheet and substrate film in acalender, as in Example 1.

A conventional 125 μm thick polyethylene terephthalate film (Mylar)which had been coated beforehand on one side with a 5 μm thick nontackyrelease layer of a polyamide (Makromelt® 6900 from Henkel) wasintroduced as a cover sheet.

A. Photochemical structuring

A printing plate was produced from the raw plate. For this purpose, itwas first necessary to produce a negative from the original. Thereafter,the cover sheet was peeled off and the negative was placed on theprinting plate. The laminate was covered with a transparent vacuum filmand exposed imagewise for 10 minutes under reduced pressure.

After removal of the negative, the printing plate was washed out in amixture of 80 parts by volume of Exxsol® D 60 and 20 parts by volume ofn-pentanol in a drum-type brush washer. The temperature of the washoutsolution was 30° C. After a washout time of 15 minutes, the printingplate had been washed out down to the adhesion-promoting mixture of thesubstrate film. The printing plate was then dried for 2 hours at 60° C.and, after standing for 12 hours, was then detackified by immersion inan aqueous bromine solution for 5 minutes.

The printing plate thus obtained is referred to as printing plate (2a).

B. Mechanical structuring

The printing plate was exposed uniformly from both sides for 10 minutes.Thereafter, the cover sheet was peeled off and the printing plate wastreated for 2 minutes in a drum-type brush washer with n-pentanol.During this procedure, the thin nontacky release layer becomes detached.The printing plate was then dried for 10 minutes at 60° C. and, aftercooling to room temperature, was detackified by immersion in an aqueousbromine solution.

The printing plate was then structured mechanically according to Example1.

The printing plate thus obtained is referred to as printing plate (2b).

COMPARATIVE EXAMPLE 2

A rubber blanket conventionally used for offset lacquering wasmechanically structured, the rubber blanket being placed on the cuttingtable of a computer-controlled cutting apparatus (e.g. Marbaplot),sucked against the table under reduced pressure and cut. The originalproduced in the computer corresponded to that used in Example 1.

The printing plate thus obtained is referred to as printing plate (3).

EXAMPLE 2

A photosensitive mixture was processed in a twin-screw extruder. Theformulation contained the following components:

40 parts of ethylene/acrylic acid/acrylate copolymer (as in Example 1)

40 parts of ethylene/propylene/diene rubber (BunaAP 251) (as in Example1)

3.0 parts of glycidyl methacrylate

5.0 parts of hexanediol diacrylate

1.0 part of benzil dimethyl ketal

1.0 part of 2,6-di-tert-butyl-p-cresol (Kerobit TBK)

5.0 parts of isophoronediamine

The melt emerging from the slot die was passed into the nip (thickness1.3 mm) of a two-roll calender, where the melt was smoothed and wasfirmly bonded to the cover sheet and substrate film.

The substrate film used was 300 μm thick, pre-coated polyethyleneterephthalate film (Hostaphan RN from Hoechst AG), which had been coatedbeforehand with a mixture of adhesion-promoting components in athickness of 5 μm.

The cover sheet employed was a 75 μm thick, uncoated polyethyleneterephthalate film (Hostaphan RN from Hoechst AG).

The laminate was peeled off by means of a vacuum suction belt. The rawplates passed through an exposure station. The residence time of theplates under the lamps and the luminous intensity of the lampscorresponded to an exposure time of 5 minutes in a 70 W exposure unit.

Mechanical structuring

The printing plate was placed on the cutting table of acomputer-controlled cutting apparatus, the cover sheet was removed, theplate was sucked against the table under reduced pressure and cuttingwas carried out according to Example 1 (production of printing plate(1b)).

The printing plate thus obtained is referred to as printing plate (4).

The results obtained with the individual printing plates are summarizedin the Table below.

                                      TABLE                                       __________________________________________________________________________                    Printing plate                                                Test parameter  (1a) (1b) (1c) (2a)                                                                             (2b) (3)  (4)                               __________________________________________________________________________    Properties of printing plate                                                  Shore A (6 mm sample)                                                                         39   40   40   46 48   /1/  50                                Adhesion printing layer/                                                                      7    9    9    8  10   8    8                                 substrate in N/2 cm /2/                                                       Tensile test /3/                                                                              210  220  220  350                                                                              400  /1/  160                               Elongation at break in %                                                      Tensile strength in N/mm.sup.2                                                                1.8  2.0  2.0  1.9                                                                              2.3  /1/  3.1                               Tear propagation strength                                                                     1.7  1.8  1.8  1.9                                                                              2.2  /1/  2.6                               according to DIN 53,507                                                       Median in N/mm                                                                Range in N/mm /4/                                                                             0    0    0    0.5                                                                              0.6  /1/  0                                 Cutting result                                                                Edge sharpness       good good    jagged                                                                             good good                              Peelability of large areas                                                                         good good    tears/5/                                                                           good good                              Peelability of negative elements                                                                   good good    moderate                                                                           poor good                              Resolution           1 mm 1 mm    5 mm 10 mm                                                                              1 mm                              Print test /6/                                                                Copies before piling                                                                          >50,000                                                                            >50,000                                                                            >50,000                                                                            500                                                                              1,000                                                                              3,000                                                                              >50,000                           Accuracy of register                                                                          good good good good                                                                             good poor good                              Swelling in lacquer /7/                                                                       9.5  6.5  5.2  0.6                                                                              0.6  0.3  3.0                               Uniformity of lacquer coating                                                                 good good good good                                                                             good squashed                                                                           good                              __________________________________________________________________________     Evaluation or explanation for the Table:                                      /1/ Cannot be determined since can only be peeled off with fabric layer       /2/ Peel angle 90°, peel speed 100 mm/min                              /3/ Tensile test, clamped length 10 cm, sample width 1.5 cm, sample           thickness 1 mm, extension rate 10 cm/min                                      /4/ The range indicates the uniformity of tearing Range 0 = no force peak     0.6 = force peaks which are up to 0.6 N/mm apart                              /5/ Strip to be peeled off tears at corners and edges which are not           cleanly cut                                                                   /6/ MANRoland 600 sheetfed offset printing press with lacquering unit,        waterbased lacquer Senolith ® Polylack, viscosity 30 sec                  /7/ Weight increase in % after storage for 24 hours in waterbased lacquer     based on relief layer, onesided swelling with substrate film             

The mechanical data (hardness, elongation at break, tear propagationstrength) of the printing plates (1a) and (1b) produced according to theinvention, which are stated in the Table, have a good agreement with thedata for the printing plates from the Comparative Experiments, i.e.printing plates (2a) and (2b). The only differences are in theuniformity of tearing according to DIN 53,507. In the force/distancediagram of the novel printing plates (1a) and (1b), no irregularities,i.e. no force peaks, are detectable. On the other hand, the printingplates of Comparative Experiments (2a) and (2b) show many force peaks.The samples tear irregularly.

This difference is decisive for the quality of mechanical structuring.The resolution of the novel printing plate (1b) is 1 mm. The sidewallsof the cutout elements are uniformly smooth. The sidewalls of thecomparative printing plate (2b) on the other hand are jagged. Theresolution of mechanical structuring is substantially lower here. Inaddition, the cuts often do not reach the corners of the image elements.During peeling, the corners are therefore raised or, in the case ofsmall elements, removed entirely. The resolution of the mechanicallystructured rubber blanket is once again lower since, on peeling, notonly the uppermost layer but also a fabric layer underneath must bepeeled off. It is difficult to find the beginning of the layer to bepeeled off. Furthermore, the fabric layer frays during peeling.

In photochemical structuring, the resolution is of course higher (0.02mm). Here, the printing plate (1a) produced according to the inventiondoes not differ substantially from the comparative printing plate (1b).The data have therefore been omitted from the Table. However, a decisiveadvantage is the fact that photochemical structuring of printing plate(1a) is possible without organic solvents.

In the print test, only printing plates (1a) and (1b) produced accordingto the invention give good results. The conventional printing plates andthe rubber plate exhibit piling after only a few sheets, the print withthe rubber blanket additionally exhibiting squash. Furthermore,in-register lacquer application by the rubber plate deteriorates duringthe print run.

We claim:
 1. A process for the production of a flexible printing platefrom a dimensionally stable printing plate, which dimensionally stableprinting plate consists essentially of a dimensionally stable substrateand a photosensitive recording layer on the substrate, which processconsists essentially of (1) uniformly exposing the photosensitiverecording layer to light to produce a uniformly exposed recording layer,(2) imagewise cutting the uniformly exposed recording layer to producenonprinting parts and printing parts of the recording layer, and (3)mechanically peeling the nonprinting parts of the recording layer awayfrom the substrate leaving a substrate and printing parts of therecording layer on the substrate.
 2. The process of claim 1, wherein aprotective film is originally present on the recording layer.
 3. Theprocess of claim 2, wherein a nontacky release layer is present betweenthe photosensitive recording layer and the protective film, whichrelease layer is removed before or after the step of imagewise cutting.4. The process of claim 1, wherein an adhesion-promoting layer ispresent between the recording layer and the dimensionally stablesubstrate.
 5. The process of claim 1, wherein the dimensionally stablesubstrate is a plastic film.
 6. The process of claim 4, wherein theadhesion of the recording layer is more than 1 N/cm and less than 10N/cm, determined at a peel angle of 90° and a peel speed of 100 mm/min.7. The process of claim 1, wherein the tensile strength of the recordinglayer is more than 0.2 N/mm² and less than 20 N/mm² determined at aclamped length of 10 cm, a sample width of 1.5 cm, a sample thickness of1 mm and an extension rate of 10 cm/min.
 8. The process of claim 1,wherein the hardness of the exposed recording layer, determined on a 6mm sample, is more than 20, and less than 80 shore A.
 9. The process ofclaim 1, wherein the photosensitive recording layer contains a mixtureof a hydrophobic and a hydrophilic binder in amounts such that theexposed recording layer, when washed out with a developer, exhibits aweight increase of >1 and <30% by weight after storage for 24 hours inwater at room temperature.
 10. The process of claim 1, wherein thephotosensitive recording layer contains a mixture of at least oneelastic binder, at least one ethylenically unsaturated compound and atleast one photoinitiator.